(1). Field of the Invention
The present invention relates generally to ties for connecting form panels to create a poured concrete wall system, and more particularly to an improved tie which is mechanically operable to be inserted through a form panel and then manipulated to retain the form panel in position, and a method for removing the form panel after the concrete has cured.
(2). Background Information
A popular wall forming system utilizes expanded polystyrene panels as forms for poured concrete walls. After the concrete has hardened, the panels may be left in place on the walls to serve as permanent insulation, or they may be stripped off to reveal the exposed concrete and permit reuse of the form panels.
Initially, these lightweight concrete forming systems utilized elongated one foot high sheets with tie slots formed along the upper and lower edges. The panels then were connected by plastic ties, the panels oriented parallel to one another and stacked vertically.
In order to permit use of a large four foot by eight foot panel as a concrete form panel, the inventor herein created a tie with an elongated connector strap and hinged end plates. The end plates could be pivoted to a position parallel to the strap, forming a small cross-section which could be easily pushed through the form panel. The end plate is then manipulated to a perpendicular position and pulled against the form panel to retain the form panel from movement outwardly off of the tie.
With both the initial systems and the four by eight sheet systems, the procedure for removing the form panels from the cured concrete wall was the same: a sharp vertical blow was applied to the end plate to break the end plate and permit removal of the form panel. A scraper was then used to scrap the projecting legs which initially interconnected the outer end plate with an inner retainer plate.
While both of these ties permitted removal of the form panels from the cured concrete wall, it was found that the large openings between the legs connecting the end plate with a retainer plate filled with residue and concrete which migrated during the pouring of the concrete. This in turn stayed within the slots formed in the form panels when the form panels were removed from the wall. Thus, it was necessary to clean out all of the slots in the form panels before the panels could truly be reused.
In addition, the vertical blow utilized to knock the end plate from the tie strap legs frequently damaged the exterior surface of the form panel. This occurred not only by the vertical blow applied to the plate, but by the affects of the scraper or hammer contacting the surface of the form panel, and gouging groves and the like in the form panel.